1. Field of the Invention
The present invention relates to a buckling device, and more particularly, to a buckling device for fastening a belt.
2. Descriptions of the Related Art
When partaking in underwater activities, users must always wear masks and flippers. The mask may be a pair of swimming goggles, a pair of diving glasses or another kind of device for covering the facial contours of the users. Generally, both the mask and the flippers are provided with a buckling device and a belt so that the belt length can be adjusted according to the figure of each user. The belt is then fastened by the buckling device around the body of the user.
In references to FIGS. 1A to 1C, a conventional buckling device 1 comprises a body 11, a snap-fitting element 12, a resilient element 13, a first pivot 17 and a second pivot 16. The snap-fitting element 12 comprises an engaging end 15 and an opposite end 14. The opposite end 14 comes into contact with the resilient element 13, while the engaging end 15 engages with a belt (not shown) wound around the second pivot 16. When the user lifts the snap-fitting element 12 upwards, the opposite end 14 rotates inwards about the first pivot 17 to abut against the resilient element 13 (i.e., the snap-fitting element 12 shown in FIG. 1C rotates counterclockwise) so that the resilient element 13 is deformed outwards to generate a pre-pressing elastic restoring force. Also, the engaging end 15 tilts outwards to disengage from the belt of the mask, the flipper or the like. Then, the belt length can be adjusted according to the figure of the user to attach the mask, the flipper or the like to the user's body firmly and properly.
However, because the resilient element 13 is integrally formed with the body 11, the resilient element 13 needs to have sufficient strength, which tends to result in an insufficient flexibility of the material when the user applies a force to the opposite end 14. Consequently, the snap-fitting element 12 cannot be pulled outwards promptly by the user, so the user has to apply a great force when adjusting the belt. As a consequence, an excessive force is often applied by the user when directly pulling the snap-fitting element 12, thereby causing material fatigue or even fractures in the resilient element 13.
FIG. 2A to FIG. 2C depict another conventional buckling device 2. The buckling device 2 comprises a body 21, a snap-fitting element 22 and two push portions 24. The body 21 comprises a pivot 26, around which a belt (not shown) of a mask, a flipper or the like is adapted to be wound. The snap-fitting element 22 comprises a snap-fitting protrusion 23 and an engaging end 25. The two push portions 24 are disposed, opposite each other, on two sides (as shown in FIGS. 2A and 2B) of the snap-fitting element 22 along an axial direction of the pivot 26. The engaging end 25 is disposed on a side of the snap-fitting element 22 adjacent to the pivot 26 to abut against a belt (not shown) that is wound around the pivot 26. The snap-fitting protrusion 23 of the snap-fitting element 22 is snap-fitted with a hole of the body 21 so that the snap-fitting element 22 can obtain a resilient force. When the two push portions 24 simultaneously receive an inwards push force, the two edges of the snap-fitting element 22 are directly pushed by the push portions 24 to arch outwards so that a gap between the engaging end 25 and the belt of the mask, the flipper or the like is increased. Then, the length of the belt can be adjusted according to the figure of the user, and the belt can be wound around the user to attach the mask or the flippers to fit the user's body comfortably. Once the user releases the push portions 24, the snap-fitting element 22 returns to its original position by virtue of the resilient force of the snap-fitting protrusion 23. The push portions 24 also return to their original positions by means of a spring disposed between the push portions 24.
Similar to the aforesaid buckling device 1, as the snap-fitting protrusion 23 is integrally formed with the snap-fitting element 22, a sufficient strength and stiffness are required to engage with the belt. However, because the material of the snap-fitting protrusion 23 is too stiff, the snap-fitting protrusion 23 is also not flexible enough, making it difficult for the snap-fitting element 22 to arch outwards promptly when being pushed by the user and, therefore, leads to poor pushing tactility of the push portions 24 when the user adjusts the belt. As a consequence, an excessive force is often applied by the user when pushing the push portions 24, thereby also causing material fatigue or even fracture of the snap-fitting protrusion 23. Moreover, when the snap-fitting element 22 is directly pushed by the push portions 24 to arch outwards, violent friction occurs between the snap-fitting element 22 and the push portions 24, making them liable to wear. As a result of the wear, the engaging end 25 will fail to deliver a sufficient engagement force when engaging with the belt and cannot be securely pressed against the belt. Even worse, the belt may fall off during use, which would endanger the life of the user.
In view of this, an urgent need exists in the art to provide a buckling device which has good pushing tactility and is less liable to fatigue, fracture and wear.